Calculators / Gravel
Crushed stone, by the ton
Gravel calculator
Driveways, paths and base layers. Enter the area and depth and get cubic yards, tons, and the bag count if you are buying it a sack at a time.
How deep, by project
| Project | Depth | Notes |
|---|---|---|
| Garden path, foot traffic | 2 in | Over landscape fabric. Deeper gravel underfoot feels loose and unstable. |
| Driveway top layer | 3–4 in | Angular crushed stone, not rounded pea gravel, or it will not lock together under tyres. |
| Driveway base course | 6–8 in | Larger crushed stone laid and compacted before the top layer goes on. |
| Under a paver or slab base | 4–6 in | Compacted in 2-inch lifts. Skipping compaction is the most common cause of a sunken patio. |
| French drain or dry well | Fill the trench | Clean washed stone with no fines, so water can move through it. |
Why gravel is ordered by weight
Mulch and soil are sold by volume; crushed stone is normally sold by the ton. Both numbers appear on the ticket above, because you need volume to work out the job and weight to place the order.
The conversion is roughly 1.35 tons per cubic yard for typical crushed limestone or granite. Wet stone weighs more, and yards weigh the truck as it leaves, so a rainy delivery day costs slightly more for the same pile.
Build a driveway in layers
A gravel driveway that lasts is not one deep layer of the same stone. It is a coarse base of 2 to 3 inch crushed rock, then a middle layer, then a top course of smaller angular stone that locks together and sheds water. Each layer gets compacted before the next goes down.
Calculate each layer separately. Enter the driveway area with a 6-inch depth for the base, note the tonnage, then run it again at 3 or 4 inches for the top course. Adding the layers together in one calculation gives the same total volume, but the yard needs to sell you two different products.
Angular versus rounded
Angular crushed stone has fractured faces that wedge against each other and stay put. Rounded stone — pea gravel, river rock — behaves like ball bearings. It is comfortable to walk on and terrible to drive on.
If you have already spread rounded stone on a drive and it migrates every time you brake, the fix is not more gravel. It is a bordered edge and an angular top course.
Common questions
How many tons of gravel do I need?
Multiply the area in square feet by the depth in feet to get cubic feet, divide by 27 for cubic yards, then multiply by about 1.35. A 12 by 40 foot driveway at 4 inches is 160 cubic feet, 5.9 cubic yards, or roughly 8 tons.
How much area does a ton of gravel cover?
Around 100 square feet at 2 inches deep, or 55 square feet at 4 inches. A ton is about three quarters of a cubic yard.
What size gravel is best for a driveway?
Angular crushed stone graded around 3/4 inch with fines for the top course, over a coarser 2–3 inch base. The fines are what let the surface bind rather than scatter.
Do I need landscape fabric under gravel?
Under a path or decorative bed, yes — it stops stone sinking into soft ground. Under a compacted driveway base, a woven geotextile helps on soft subgrade, but ordinary weed fabric will shred and is not worth laying.
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Mulch · Pea gravel · River rock · Topsoil · Sand